I havent't kept track of the time I spent on it because i'm doing it on a hobby basis.

But as a rough estimation I can tell you that i've spent most of my free time on it, which very roughly averages to 20hours a week, and since I've been on it for nearly 6 months now I can conclude that it cost me around 500 hours of work(and fun also). Thats
is definitely much more time than I expected when I first started it!